(xxxv) CRUSTACEA CASPIA. 69 
ing the dorsal part of the last 2 segments of mesosome quite uncovered, la- 
teral lobes not even obtecting the sides of the last segment (see fig. 18), 
cephalie part about as broad as the ist segment of metasome, and having 
the infero-lateral corners produced to acute anteriorly curving projections, 
rather conspicuous also in the dorsal view of the animal (see fig. 1 & 2), 
anterior edge considerably produced in the middle, though evenly rounded 
at the tip. Eyes (see fig. 2) rather narrow, nearly cylindrical in form, and 
considerably projecting laterally beyond the sides of the carapace, corneal 
part but slightly expanded, and occupying dorsally only 1 of the length of 
the eye, its inner edge nearly straight. Superior antennæ with the peduncle 
(fig. 3) but little longer than the eyes, last joint having in female only a 
single plumose seta at the inner corner, the latter being in male (see fig. 19) 
produced to a narrow digitiform process, male appendage (fig. 20) scarcely 
more than half the length of the peduncle and very narrow. Inferior antenne 
(figs. 4 & 21) with the outer corner of the basal part produced to a very 
strong anteriorly curving spiniform projection, scale in female (fig. 4) about 
twice the length of the peduncle of the superior antenne, and regularly lan- 
ceolate in form, about 4 times as long as it is broad, with the inner edge 
somewhat arched in its proximal part, apical segment occupying about '/, of 
the length of the scale and bearing 12 of the marginal setze, 3 issuing from 
the tip; apical segment in male (see fig. 21) freely movable upon the remain- 
ing part of the scale, by the aid of a strong muscle quite wanting in female, 
its tip (fig. 21) produced to a spiniform or nearly hook-shaped point curved 
downwards. Gnathopoda (fig. 11) with the basal part very large and fringed 
interiorly with strong plumose setae, apical spines (see fig. 12) about 13 in 
number, all of same appearance, though the median one (the dactylus) ap- 
pears a little stronger than the others. Pereiopoda (fig. 13) with the ischial 
and meral joints nearly equal-sized, and having on the inner edge numerous 
fascicles of slender setæ, tarsal part about same length, with the 1st joint 
somewhat longer than the other 2 combined, 3rd joint (see fig. 14) forming 
at the end interiorly a slight nodular projection armed with 2 short spines, 
dactylar joint (ibid.) very small and having at the base of the terminal claw 
2 somewhat unequal spines. Outer sexual appendages of male (fig. 22) di- 
stinctly bilobular at the tip, the anterior lobe more projecting and fringed 
with long stiff bristles. Fourth pair of pleopoda in male (fig. 24) reaching 
scarcely to the end of the last segment of metasome, basal part produced 
at the outer corner to a triangular projection, outer ramus somewhat irre- 
gularly twisted, having the inner edge biangular on the middle and armed, 
at the base of the flagellar part, with a small hooked projection. Telson 
(fig. 16) much shorter than the last segment of metasome, and rather broad 
Mélanges biologiques. T. XIII, p. 417. 
